A BIODEGRADABLE INJECTABLE IMPLANT FOR DELIVERING MICROMOLECULES AND MACROMOLECULES USING POLY(LACTIC-CO-GLYCOLIC) ACID (PLGA) COPOLYMERS

Biodegradable polymers are used in diffusion controlled, swelling cont rolled and chemically controlled delivery systems. In this study, PLGA copolymers were used in a formulation which forms a gel matrix immedi ately on contact with aqueous fluids. This property of the formulation can circumvent the need for making a surgical incision to implant the matrix. The gel matrix thus formed will release the drug slowly (over a period of weeks to months) and ultimately biodegrade depending on t he composition of the polymer used. In vitro release studies using sma ll molecules and macromolecules, such as proteins, indicate that the d rug release is influenced by the concentration of the polymer, physico chemical properties of the drug, method of incorporation of the drug i n the formulation and the presence of other excipients. The drug relea se can therefore be modified to suit the desired release characteristi cs. This novel formulation design for a biodegradable injectable impla nt can provide prolonged release while avoiding the necessity for surg ical procedures.